The invention relates to a hub assembly and more specifically to a noise dampener assembly for mounting a circular blade on the drive shaft of a circular saw. The noise dampener hub assembly is particularly beneficial when used in cutting large format tile and slab stone.
In the past, the power source for small sawing systems was an electric motor using a V-belt and/or direct drive that turns a diamond rimmed cutting disc. The trend to use small tile and stone saws for cutting stone is to use a circular saw having a rotating cutting disc. The new trend is to use a mass-produced small tool that incorporates an electric motor and a worm or helical gear reduction such as a worm drive “skill saw design.” Another popular power source is a hand held grinder, again incorporating a small motor and reduction gear. These power units are now being used in many tile and stone saws for the power source. These mass-produced portable saws and grinders are used for the following reasons: 1) a low cost and reliable power source, 2) a very desirable weight to a torque ratio in a small portable package and 3) a power source that can be quickly changed if defective or worn out.
A major concern in the industry is the noise intensity produced during cutting operations on tile and stone. As the operator of a saw is continually exposed to the loud noise of the cutting operation, over time, it will cause a hearing problem.
Attempts have been made to reduce the sound intensity of the circular diamond blade. There is an Italian diamond blade on the market that has reduced some of the intensity of the sound during the cutting operation. The sound reduction in this design is accomplished by two methods. First, there is a series of laser cuts through the matrix on the outer rim of the blade and proceeding for a distance into the core of the blade. These “fine kerf” cuts proceed around the perimeter of the blade. This technology dampens the vibration or harmonics in the core of the blade. The second form of technology that dampens the harmonics or vibration in the core of the blade is that the core itself is a laminated disc. The disc is actually two pieces of metal laminated together with a copper or soft bond such as a copper amalgam. These combined features provide an improved reduction in decibel levels.
It is an object of the invention to reduce the overall sound produced by the radial diamond saw blades, especially with a higher percentage of noise reduction in the high pitch decibel range.
It is also an object of the invention to produce a novel noise dampener hub assembly that will result in a significant reduction in shop noise fatigue.
It is another object of the invention to provide a novel noise dampener hub assembly that can be used to provide a dramatic reduction in vibration in core deflection of the radial saw blades.
It is an additional object of the invention to provide a novel noise dampener hub assembly that produces a very noticeable increase in the blade life and which also produces a decrease in premature diamond loss from the blade.
Another problem that exists in the industry is created by the fact that diamond rimed circular discs are never perfectly round. The cost of the blade often reflects the quality assurance if regarding the consistent roundness of the blade. Most of the inexpensive power supplies have inherent “run-out” on spindle rotation. Thus the spindle run-out and the blade being out-of-round results in what is called a “wear-in process,” in other words, “truing up” of the blade. From then on, if the blade is not removed or its position is unchanged relative to the spindle, the blade will have a normal functional life. When an operator wants to cut another type of stone, he usually has to change blades. When the original blade is remounted, the exact spindle location from the “wear-in process” is lost. Thus, the “wear-in process” has to start over again. On small portable hand cutting machines no provision is made for a blade to be mounted to the power spindle in the exact position each time. Thus, premature blade wear is experienced.
It is an object of the invention to provide a noise dampener hub assembly that will allow a blade to be removed and replaced in such a manner that it is always in the exact same position that it was originally in the noise hub assembly.